Digital hierarchy

A world organized around centralized control, strict intellectual property rights, and hierarchies of credentialed experts is under siege. A radically different order of society based on open access, decentralized creativity, collaborative intelligence, and cheap and easy sharing is ascendant. —from Viral Spiral

Synchronous Digital Hierarchy (SDH) and Synchronous Optical Network (SONET)
The synchronous hierarchy digital (SDH) is emergingthe as universal technology for transmission telecommunications in networks. the publication Since first of international standards by ITU-T in 1989, SDH equipment has been rapidly developedand deployed across the world,andisrapidlytakingoverfromitspredecessor,thePlesiochronousDigitalHierarchy (PDH).ThischapterdescribesSDHandtheNorthAmericanequivalentofSDH,SONET (SynchronousOpticalNetwork),fromwhichitgrew...

In the last two years, optical networking has risen into the public consciousness
in many different ways. It has become the next great technological
thing — businesses want it, service providers want to sell it, device
manufacturers want to provide equipment, and component manufacturers
are scrambling to supply pieces and parts to all of them. At the time of
this writing, an 18-month backlog on optical fiber and some optical amplifiers
exists because of the enormous and unanticipated demand for highbandwidth
optical connectivity.

MTP is divided into three parts, located at levels 1, 2, and 3 of the SS7 hierarchy. The main functions of these parts are outlined below [l-5]. MTP Level 7 (MTp7) is the physical signaling data link (SDL), which consists of a pair of 64 kb/s digital transmission channels, and transports SS7 signal units between two signaling points. MTPl is described in Section 8.2. MTf Level 2 (MTf2).

The first five editions of this book were based on the idea that a computer can
be regarded as a hierarchy of levels, each one performing some well-defined function.
This fundamental concept is as valid today as it was when the first edition
came out, so it has been retained as the basis for the sixth edition. As in the first
five editions, the digital logic level, the microarchitecture level, the instruction set
architecture level, the operating-system machine level, and the assembly language
level are all discussed in detail....

Memory is pervasive in digital products. Consider, for example, the personal computer (PC). It has main memory, video memory, translation ROMs, shadow ROMs, scratchpad memory, hard disk, ﬂoppy disk, CDROM, and various other kinds of storage distributed throughout. In addition, the die that contains the microprocessor may also contain one or more levels of cache. A typical PC is depicted in the block diagram of Figure 10.1. It is basically a memory hierarchy connected by several buses and adapters and controlled by a CPU. ...

The advent of the Internet, digital connectivity, the explosion and use of e -commerce and e-
business models in the private sector are pressuring the public sector to rethink hierarchical,
bureaucratic organizational models. Customers, citizens and businesses are faced every day
with new innovative e -business and e -commerce models implemented by the private sector
and made possible by ICT tools and applications, are requiring the same from governmental
organizations.